Is there a way of making the smart folder's contents public while keeping the content's containing folder from appearing to the public?
What you can do is create a folder called “events”. Then what I like to do is restrict the addable types to this folder so that users can only add events to this folder. To do this, click on “add item” from the action tabs when you are logged in Plone. At the bottom, select “restrict” to restrict only events.
You can the keep this folder as a “Public Draft” and then in
select “Filter on workflow state” and select “Published”. Now only published items will appear within your navigation portlet while your smart folder will be published.
Also by restricting addable types you can control where users can add events. This way you don’t have events being added all over your entire Plone site.